London Terror Bombings Kill 50, Wound 700

British Prime Ministe Tony Blair blamed Islamic extremists and said the bombings were designed to coincide with the opening in Scotland of a G-8 summit of the world's most powerful leaders. Foreign Secretary Jack Straw said the bombings, which came the day after London won the bid to host the 2012 Olympics, have the "hallmarks of an al-Qaida-related attack."

Police said there had been no warning and that the blasts at three subway stations went off within 26 minutes, starting at 8:51 a.m. in an Underground train just outside the financial district. Authorities initially blamed a power surge but realized it was a terror attack after the bus bombing near the British Museum at 9:47 a.m., less than an hour after the first explosion.

rapped passengers in the Underground railway threw themselves on the floor, some sobbing. As subway cars quickly filled with smoke, people used their umbrellas to try to break the windows so that they could get air. Passengers emerged from the Underground covered with blood and soot. On the street, in a light rain, buses ferried the wounded, and medics used a hotel as a hospital.

The attack on London brought out a steeliness that recalled Britain under the blitz of German bombers in World War II, when many Londoners sought refuge in the Underground, site of Thursday's carnage.

The Bush administration raised the terror alert a notch to code orange for the nation's mass transit systems on Thursday, responding to a spate of deadly rush-hour bus and subway bombings in London.

The terror alert has not been raised in the United States since last August, when the Homeland Security Department increased the threat level to orange — or high — for the financial sector in New York and New Jersey in the run up to the November elections.

President Bush, in Scotland for a meeting of the Group of Eight leaders, conferred in a secure video conference with national security and homeland security officials in Washington.

U.S. officials were trying to determine, meanwhile, whether an al-Qaida cell's claim of responsibility for the London attacks was credible. A U.S. official speaking on condition of anonymity because events were still unfolding said analysts were sifting through recent intelligence for evidence that other attacks might be in the works.

President Bush Cautions Americans

President Bush warned Americans on Thursday to be "extra vigilant" as they head to work after the deadly explosions in London. &nbsp

Bush said he spoke with federal homeland security officials back in Washington.

"I instructed them to be in touch with local and state officials about the facts of what took place here in London," Bush told reporters from a summit of world leaders here.

Bush urged caution "as our folks start heading to work."

"The war on terrorism goes on," he said. "We will not yield to these people."

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